AIDS vaccine development: perspectives, challenges & hopes.

The worldwide quest for an AIDS vaccine represents an unprecedented scientific and human challenge for the 21st century. Preventive vaccines represent our only long-term hope to stop the epidemic. AIDS vaccines must be seen as the ultimate prevention tool that will complement the existing prevention strategies in place. The acceleration of vaccine development through the parallel exploration of several scientific approaches and implementation of clinical trials are the best and probably only way to reach this goal, and the best vaccines have moved into phase II and efficacy trials. Ideally an AIDS vaccine should induce both neutralizing antibodies against HIV-1 primary isolates and cell-mediated responses. AIDS vaccines could prevent either HIV infection or progression to disease and decrease transmission by reducing the HIV viral load. Most of the vaccine approaches developed so far aim at inducing cell-mediated immune responses. New vector-based vaccines include modified vaccinia Ankara, adeno-associated virus, adenovirus and alpha viruses. Considerable efforts are on to develop vaccines that would induce neutralizing antibodies. All vaccines tested so far in humans have proven to be safe. This long-term endeavour requires strong and renewed political leadership and commitment, flexibility of processes, medical and scientific dedication and collaboration on a mission mode along with community participation for immediate action. Recent developments in India highlight clearly the commitment of the Government of India and the scientific community to a long-term global effort to develop an AIDS vaccine.